RWTraceLevelFilter Class Reference
[Execution Tracing]

A handle class for a single-client filter that lets only events of the supplied severity level or higher pass through. More...

#include <rw/trace/RWTraceLevelFilter.h>

Inheritance diagram for RWTraceLevelFilter:

List of all members.

Public Member Functions
	RWTraceLevelFilter (RWTraceEventSeverity level=RW_TRACE_LEVEL_NONE)
	RWTraceLevelFilter (RWTraceLevelFilterImp *bodyP)
	RWTraceLevelFilter (RWStaticCtor)
	RWTraceLevelFilter (const RWTraceLevelFilter &second)
	~RWTraceLevelFilter (void)
RWTraceEventSeverity	getLevel () const
void	setLevel (RWTraceEventSeverity level)

---

Detailed Description

RWTraceLevelFilter is a single-client filter that lets only events of the supplied severity level or higher pass through.

Examples

 #define RW_USER_TRACE_LEVEL 8                               //1

 #include <rw/trace/trace.h>

 int main()
 {
   RWTraceOstreamClient myTraceClient(cerr);                 //2

   // create filter that only lets INFO and more important events
   // pass through
   RWTraceLevelFilter myTraceLevelFilter(RW_TRACE_LEVEL_INFO);//3

   // connect client to level filter
   myTraceClient.connect(myTraceLevelFilter);                //4

   // connect level filter to manager
   myTraceLevelFilter.connectToManager();                    //5

   RW_USER_TRACEABLE_FUNCTION("main");                       //6

   // generate some trace information
   RW_USER_TRACE_INFO("This info level message should be seen.");

   // change the level
   myTraceLevelFilter.setLevel(RW_TRACE_LEVEL_ERROR);        //7

   // generate some more trace information
   RW_USER_TRACE_INFO("This info level message should not be
                                                      seen.");
   RW_USER_TRACE_ERROR("This error level message should be
                                                     seen.");

   return 0;
 }

The following is a description of each program line:

//1 Compile in all trace macros by setting the user trace level macro to 8. This line sets the maximum trace level to compile into the code. To compile in all the trace macros, the level is set to the maximum 8 (Entry/Exit). You could also define the trace level on the command line for your compiler, using the flag -DRW_USER_TRACE_LEVEL=8.

//2 Create a normal std::ostream client to display the trace information.

//3 Instantiate an RWTraceLevelFilter. The constructor takes the maximum level of trace messages to pass through. You can pass an integer level number (see Section 6.1.3 of the Threads Module User's Guide) or use one of the symbolic constants, as in this line. Pass 0 to filter out all trace messages.

//4 Connect the client to the level filter.

//5 Then connect the filter to the trace manager.

//6 Declare the function as traceable, so you can use trace event generation macros in this function.

//7 Change the cutoff level on the level filter, using the setLevel() function.

The symbolic constants referred to in line //3 are defined in the file rw/trace/RWTraceEventSeverity.h. They cannot be used when setting the RW_USER_TRACE_LEVEL macro, because this macro needs to be set before including any trace header files. They include:

• RW_TRACE_LEVEL_FATAL
• RW_TRACE_LEVEL_ERROR
• RW_TRACE_LEVEL_WARNING
• RW_TRACE_LEVEL_INFO
• RW_TRACE_LEVEL_TEST
• RW_TRACE_LEVEL_DEBUG
• RW_TRACE_LEVEL_ENTRY
• RW_TRACE_LEVEL_ENTRY

All of these constants map directly to the appropriate severity level. RW_TRACE_LEVEL_NONE filters out all trace messages. It is equivalent to zero.

---

Constructor & Destructor Documentation

RWTraceLevelFilter::RWTraceLevelFilter

(

RWTraceEventSeverity

level = RW_TRACE_LEVEL_NONE

)

Default constructor. If no level is supplied, the default is RW_TRACE_LEVEL_NONE. In this case, no events are passed on.

RWTraceLevelFilter::RWTraceLevelFilter

(

RWTraceLevelFilterImp *

bodyP

)

Attaches to and increments the reference count on bodyP .

RWTraceLevelFilter::RWTraceLevelFilter

(

RWStaticCtor

)

Constructs a global static handle instance (may be used before being constructed).

RWTraceLevelFilter::RWTraceLevelFilter

(

const RWTraceLevelFilter &

second

)

Attaches to and increments the reference count on the body of second .

RWTraceLevelFilter::~RWTraceLevelFilter

(

void

)

Destructor.

---

Member Function Documentation

RWTraceEventSeverity RWTraceLevelFilter::getLevel

(

)

const

Returns the filter's severity level.

void RWTraceLevelFilter::setLevel

(

RWTraceEventSeverity

level

)

Sets the severity level for the filter.